The Lonely Guy

The Lonely Guy is a 1984 romantic comedy film, directed by Arthur Hiller and starring Steve Martin. The screenplay is credited to Ed. Weinberger and Stan Daniels of Taxi as well as Neil Simon for adaptation, and is based on the 1978 book The Lonely Guys Book of Life by Bruce Jay Friedman.

When shy Larry Hubbard Steve Martin, a greeting card writer, finds his girlfriend Danielle Robyn Douglass in bed with another man, he is forced to begin a new life as a lonely guy. Larry befriends fellow lonely guy Warren Charles Grodin, who considers committing suicide.After going through a period of terrible luck with women, Larry meets Iris Judith Ivey, who has dated lonely guys before. She gives Larry her number but he loses it due to a few mishaps. ........

Source: Wikipedia